The present invention is directed toward emulsion pressure sensitive adhesives which are non-ghosting.
Generally pressure sensitive adhesives are based upon styrene-butadiene polymers blended with tackifiers and dissolved in a solvent. The solvent is then evaporated to leave behind an adhesive film. The use of solvent based adhesives is however decreasing due to many undesirable factors such as cost, odor and potential health problems caused by the solvent evaporating into the atmosphere.
One alternative to solvent based adhesives is emulsion based adhesives. An obstacle encountered with emulsion based adhesives is a lack of cohesive strength which results in a deposit or residue of the adhesive on the adhered surface when the adhesive film is attempted to be removed. This phenomena is generally referred to as "ghosting". This ghosting phenomena is predominantly due to a weakness in the latex component of the pressure sensitive adhesive. Consequently it is desirable to formulate an emulsion polymer which could be employed in preparing a non-ghosting pressure sensitive adhesive.